NoSafetySmokingFirst is similar to, but distinct from, the more widely known “DontDeadOpenInside” format.
In a DontDeadOpenInside, the text reads correctly top to bottom, but visual cues (like colouration, horizontal proximity, or vertical separation) lead you to try to read it left to right. In a NoSafetySmokingFirst, the text reads correctly left to right, but visual cues (like colouration, vertical proximity, or horizontal separation) lead you to try to read it top to bottom.